Control and supervisory system



was my 2,1929.

UNITED STATES PATENT OFFICE.

HENRY L. HOITILNN, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO WESTERN ELEC- TRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION 01! NEW YORK.

CONTROL AND SUPERVISOBY SYSTEM.

Application filed November 26, 1921. Serial No. 518,007.

This invention relates to control and supervisory systems, and particularly to such systems in which switches or other objects may be remotely controlled and supervised.

5 The invention is particularly adapted for use in connection with automatic switches or circuit breakers employed with power lines.

' 7 It is an object of the invention to provide a single conductor per switch supervisor 10 system in which control and answer-bac impulses are transmitted over the same line.

It is another object of the invention to produce a system of the above type, which includes a minimum number of operating elements, is reliable and is rapid in operation, indicating at the central station the position of a switch a very few seconds after the switch has operated.

Another object of the invention is to provide means for preventing the normal functioning of the answer-back mechanism when the main line becomes accidentally grounded.

To this end, the invention provides a polarized receiving relay at thecentral station for each power switch in the circuit, each of these relays being adapted to control the operation of suitable indicating devices, and at the substation provides a pair of relays through the windings of which the signaling current is led-over a single conductor to the polarized relay at the control station. The relays at the substation are controlled by means of a'manually operated key to operate one or the other of these relays, which control the operation of solenoids for operating the power switch. A safety circuit is also provided, common to a number of switches connected in multiple, for preventing the normal functioning of the answer-back mechanism when the main line becomes accidentally grounded, and thereby to notify the attendant of the trouble on the circuit. By means of this safety circuit theoperation of a switch automatically u on the grounding .of its line conductor is a so prevented.

Other objects and features of the invention will appear from a consideration of the following'description taken in conjunction with the accompanying drawings and the appended claims.

In the drawings, Fig. 1 illustrates schemati'cally a marginal relay circuit, embodylng the features of the invention; while Fig. 2 illustrates schematically, .a non-marginal modification thereof.

1 Referring first to Fig. 1, the reference letters A and B indicate, respectively, a con trol station and a -substation, the latter being provided with a plurality of power sw tc es 10 and 11, only two such switchesbeing shown for the sake of clearness. The power switch 10 carries a contact 12 designed to engage with one or the other of contacts 13 and 14 allotted to this particular switch. The switch 11 carries a corresponding contact 15, adapted to engage with each of contacts 16 or 17. Whether the contact 13 or 14 is engagedby switch contact 12 depends upon the position of the power switch 10. Similarly, the position of the switch 11 determines the position of its contact 15 with respect to its associated contacts 16 and 17. The power switches are provided with additional contacts so that upon their openin or closing, a circuit will be completed or e ecting the operation of indicating mechanism and for controlling the operation of the power switch solenoids as will be hereinafter described. Associated with the power switch 10 are a pair of low resistance relays 18 and 19 adapted to control the operation of the power switch controlling solenoids, as hereinafter more fully described, similar low resistance relays 20 and 21 being asso ciated with the power switch 11.

The contact 12 of switch 10 is connected through line conductor 22 with a high. re-

, sistance polarized relay 23 with which there is associated a pair of electric lamps 25 and 26 at the central station A; while the auxiliary contact 15 of switch 11 is connected through the line 27t0 a high resistance polarized relay 28 with which there is associated the lamps 29 and 30. The polarized relays 23 and 28 remain in operative position only when energized and return to a neutral position under the action of suitable sprin s whenever the operating current is cut 0%. .One or the other of each of these pairs of lamps is normally lighted, current being supplied to the lamps 25 and 26 by a battery 31, and current being supplied to the lamps 29 and 30 by a battery 32 through contacts associated with the respective polarized relays. Thus the attendant at the cen- 1'0 tral statlon, by observing the lamp which is lighted, is informed of the position of any given power switch. In practice, it is preferred to have thelamps 25 and 29 red, and the lamps 26 and 30 green. The lighting of a red lamp informs the attendant that a certain power switch is closed, while the lighting of a green lamp will at once indicate that a particular switch has .been moved to the open position.

The low resistance relays 18 and 19 at the substation B are controlled by means of a manually operated key 33 adapted upon its operation to complete a short circuit for the high resistance relay 23 and completing an operating circuit for one or the other of the low resistance relays 18 or 19. A similar key 34 is provided to control the operation of the low resistance relays 20 and 21. A safety circuit is provided, common to both of the switches,comprising a relay operated by either key 33 or key 34 to prevent the operation of the answer-back mechanism .when either of the main lines 22 or 27 becomes accidentally grounded.

The operation of the system is as follows: the power switch 10 is considered to be closed, the red indicating lamp 25 at the central station being lighted as shown in the drawing. The operation of the key 33 establishes a circuit from ground through key contact 36, line conductor 22, switch contacts 12 and 13, winding of relay 19, contact 37 of relay 18, tothe positive side of battery 38, to ground, thus energizing relay 19 and at the same time short-circuiting the polarized relay 23, permitting the relay to return to neutral position, thus extinguishing the lamp 25. The operation of the key 33 at the same time establishes an energizing circuit for the relay 35 from ground, through key contact 39, winding of relay 35, battery'40 to ground, thus closing contact 41. The energization of' the low resistance relay 19 closes contact 42, thereby establishing a circuit from battery 40, through contact 41, and armature of relay 35, operating winding 43'of the power switch 10, contact 42 and armature of the relay 19, to ground, thus energizing the switch-operatin winding 43. The energization of the win ing 43, which may be of the solenoid type, opens contact 13 and moves the auxi ia ry switch contact 12 into engagement with the contact 14. The energization of relay 19 also closes contact 44, establishing a holding circuit for the'relay 19 during the time interval when switch contact 12 is passing from contact 13 to 14, during which time the normal energizing circuit is broken. This holding circuit extends from the positive side of battery 38, through the armature and contact 37 of relay 18, winding of relay 19, contact 44 and armature of relay 19, conductor 22, contact 36 of control'key 33, to ground. As long as key 33 is held closed, relay 19 is energized and keeps contact 46 open and thereby prevents the establishment of an energizing circuit for therelay 18, the operation of which establishes an operating circuit for switch-opening solenoids 49. Thus the continued opening operatively connected through line conductor 22 to the substation B, and the answer-back signal may be received. This signaling circuit is established from the negative side of battery 38 through the armature and contact 46 of relay 19, winding of relay 18, switch contacts 14 and 12, line conductor 22, through the windings of polarized relay 23 to ground. The windings of the polarized relay 23 being energized by current of negative polarity, the armature of this relay is moved into engagement with contact 47.

Since the winding of relay 18 is of low resistance and the windings of the polarized relay 23 of high resistance, the relay 18 will not be energized upon the completion of this circuit. The closing of contact 47 completes an energizing circuit for the lam 26 which extends from the positive side of attery 31 through lamp 26, contact 47, armature of relay 23, to the negative side of. battery. The lighting of the green lamp 26" informs the attendant at the central station that the power switch 10 has been moved to the open position. When it is desired to again close the power switch 10, the opera tion of the key 33 will complete an energizing circuit for the relay 18, extending from ground, through key contact 36, line conductor 22, switchcontacts 12 and 14, winding of relay 18, contact 46 and armature of relay 19, negative side of battery 38 to ground. The energization of the relay 18 closes contact-48 thus completing an energizing circuit or the switch-controlling solenoid 49, extending from battery 40 1 through contact 41 and armature relay 45, which has been closed by the closure of key contact 39 in the manner described above,

through winding 49, contact 48, to ground.

The energization of the switch-controlling winding 49 closes the power switch 10, at the same time carrying the associated contact 12 over to the contact 13. The holding circuit for the'relay 18 is similar to that described for the relay 19, except that in this case it isicontrolled by contact 50 instead of 44. When the key 33 is released, the answer-back signal may betransmittedover the line conductor 22 in the manner described above. The operation of the control and answer-back mechanism associated with the power switch'll is the same as that de- I scribed for the Switch 10.- It will'be obvious that through the use of the safety circuit,

both ground and battery are. controlled by the key 33. Thus an accidental ground between stations A and B will fail to operate ing contact 41 of relay 35. This circuit is controlled only by the contact 39 of key 33 or the corresponding contact of key 34' at the central station. It will be evident that when the line 22 is accidentally grounded, current will be cut off from the relay 23, and this relay will therefore return to its neutral position, extinguishin whichever lamp happens to be lighted. T e attendant at the station A, seeing that both of the lamps 25 and 26 are extinguished, will at once beapprised of the trouble on the line and may take steps to correct it. the attendant will not operate either of the control keys 33 or 34 until the trouble on the line has been corrected, and without the operation of one of these keys, as pointed out above, the accidental ground will not of itself cause the operation of any power switch.

letters A and B designate, respectively, a central control station and a substation, as in the case of Fig. 1 described above, the substation B contalning a plurality of power switches 110 and 111, only two such switches being shown for the sake of clearness. The power switch 110 is provided with a circuit controllin contact 112, adapted for engagement witfi either of contacts 113 and 114, while the switch 111 is provided with a contact 115 and associated contacts 116 and 117.-

A pair of relays 118 and 119 are associated with the power switch 110 and corresponding relays 120 and 121 are associated with the switch 111 for controlling the switchopening and closing magnets as described above. The switch contact 112 is connected through line conductor 122 to a polarized relay 123 with which are associated electric lamps 125 and 126 and energizing battery 131, whiles'witch contact 115 is connected through line conductor 127 to a polarized relay 128 with which there are associated electric lamps 129 and 130 and energizing battery 132. Associated-with the controlling apparatus of power switch 110 is a relay 134, normally energized over a circuit ex tending from battery 135, through the winding of rela 134, contact 136 of relay 137,

' armature or relay 137, to ground. The relay 137 is adapted to be energized upon the closure of key contact 138 at central'station A, the energizing circuit being traceable from a source of alternating current 139, through key contact 138, line conductor 122, primary winding of repeating coil 140, switch con.-. tacts 112 and-113, armature and contact 17 7 of relay 134, resistance 176, positive side of Usually,

battery 167, to ground, a current thus being induced in the secondary winding of coil 140, completin a local energizing circuit for the relay 13 After relay 137 pulls up its armature, the circuit of the primary winding 140 is no longer through battery 167, but is traceable from generator 139,

through key contact 138, line conductor 122,

primary winding 140, contact 158, and armature of relay 137, to ground. A relay 142 is associated with the power switch controlling mechanism of switch 111 and is normally energized, in the manner described above, over a circuit extending from battery 143, winding of rela 142, contact 144 ,of relay 145, armature o relay 145, to ground. Re lay 145 is adapted to be controlled over a circuit extending from generator 139, through key contact 146, line conductor 127, the primary winding of repeating coil 147, and thence to ground in the manner described above. Instead of providing a sepa rate safety circuit controllin contact on the manually-operated control eys, as in the marginal circuit shown inFig. 1, a master key 148 is. provided, the operation of which Referring now to Fig. 2, the reference completes an energizing circuit for a master control relay 149, extending from battery 150, through winding of relay 149, key 148 and key contact 151, to ground, thus closing the contact 152 of the relay 149.

The operation of the system is as follows: the closure of key contact 138 establishes an energizing circuitfor the relay 137 as v previously described, opening contact 136 and deenergizin'g relay 134. At the same time, the opening of key contact166 deen-- ergizes polarized relay 123, permitting its armature to return to its neutral position, thus extinguishing the lamp 125 in the manner described in connection with the system shown in Fig. 1. The deener ation' of relay 134 permits the closure '0 contacts 154 and 155, and establishes an energizing circuit for the relay 119, which extends from.

battery 156 through the armature and contact 157 of relay 118, winding of relay 119, contact 154 and armature of relay 134, switch contacts 113 and 112, contact 158 of relay 137 armature of relay 137 to ground.

The energization of relay 119 closes contacts 160 and 161, and opens contact 159. I

The closure of contact 151 of master key 148 now operates master control relay 149, closing contact 152 and establishing an operat-' ing circuit for windin 162 of power switch 110, this circuit exten ing from battery 150, through contact 152, armaturevof relay 149,

solenoid winding 162 of switch 110, con--1-25 tact 160 and armature of relay 119, to ground. The energization of winding 162 breaks contact 113, movin switch contact -112 over to contact 114. order to prevent furt-her operation of the switch 110 while the key contact 138 remains closed,

I a holding circuit for .the relay*119 is established from battery 156, armature of relay 118, contact 157, winding of relay 119, contact 154 and armature of relay 134, contact 161 and armature ofrelay 119, to ground. The circuit thus established provides a holding circuit for the relay 119 during the time interval in which contact 112 of power switch 110 is moving from contact 113 over to engagement with contact 114, breaking the normal energizing circuit of relay 119. The continued energization of relay 119 prevents the closure of contact 159 which controls an energizing circuit for the relay 118 which, through its contact 164, controls ancontact 136, through contacts 114 and 112 of power switch 110, primary windin of repeating coil 140, key contact 166, win ings of polarized relay 123 to ground.- This current flow of negative potential causes relay 123 to move its armature into engagement with contact 171. This operation establishes an energizing circuit for lamp 126, extend-' ing from the positive side of battery 131, through lamp 126, contact 171 and armature v of relay 123, to the other side of battery 131, thus lighting lamp 126, thereby informing the attendant that power switch 110 has been moved to the open position. When it is desired to again close the main contacts of power switch 110, the closure of key contact 138 breaks contact 136 of relay 137,

as described above, thus breaking the circuit of normally energized relay 134 and closing contacts 154 and 155. The closure of contact 158 of' relay 137 establishes an energizing circuit for relay 118 which extends from battery 173, through armature and contact 159 of relay 119, through the winding of relay 118, contact 155 and armature of relay 134, contacts 114 and 112 of power switch 110, contact 158 and armature of relay 137, to ground. The energization of relay 118 over the circuit just traced, closes contacts164 and 174 and opens contact 157. The operation of masterkey 148 now closes contact 152 of control relay 149,

establishing an energizing circuit for solenoid wind ng 165, this circuit extending from battery 150, c0ntact152 and armature of relay 149, solenoid winding 165, contact 164 and armature of relay 118, to ground, thusbreaking switch contact 114 and carrying switch contact 112 into engagement with and armature of relay 118, to ground, thuspreventing thev closure of contact 157 of relay 118 and the "subsequent energization of relay 119 during the interval when switch contact 112 is changing its position. The

answer-back circuitin this case is similar to that previously traced and extends from the positive side of battery 167, through resistance 176, contact 177 and armature of relay 134, contacts 113 and 112 of power switch 110, primary winding of coil 140, key contact 166, windings of polarized relay 123, to ground, establishin a local energizing circuit for lamp 125trough relay contact 170. The control and answer-back mechanism associated with all other power switches on the line, such as switch 111, is similar to that described for switch 110.

If the line 122 should accidentally become grounded, the relay 123 would be deenergized and its armature would return to its neutral position, thus extinguishing whichever lamp appened to be lighted. The extinguishing of both lamps would at once indicate to the attendant at the station A that trouble existed on the line and that steps should be taken to remove it. In the case of the system shown in Fig. 2, however, if the master key 148 is operated when the line 122 is grounded, the power switch 110 would not operate as it would in the case of the system shown in Fig. 1, since'in order to operate the power switch 110 it is necessary to impress alternating current from the source 139 on the line 122 which cannot be done without closing the key contact 138. Thus, by using this system, when one line becomes accidentally grounded, the others may still be operated without any danger of further affecting the grounded line.

It will be seen that a system embodying the features of this invention requires only a single line for each switch in the circuit for connecting the central station and the remote station over which both controlling and signaling impulses are transmitted, thus doing awa with much intricate mechanism and consi erably lessening the cost of the system. It will also be seen that b means of the safety circuit herein provi ed and made common to any number of power switches connected in multiple, the proper functioning of the answer-back signal is prevented when the mainline becomes accidentally grounded, thereby. effectually notifying the attendant that the line has become grounded between the two stations. As in the case of the system described in connection with Fig. 1, both ground and battery circuits in the system shown in Fig. 2 are controlled from central station A, it being impossible, in this case, to operate a power .swltch by applying a ground between the stations until the energizing circuit for the switch operating windmgs is closed by the closure of key contact 151 at the central station.

What is claimed is:

1. In a remote control system, a central station, a remote station, an electromagnetic device to be controlled thereat, a marginal relay at the remote station, a signal controlrelay, a circuit including said control rela and said marginal relay, a manual switch at the central station which when closed shunts said signal control relay to cause said marginal relay to be operated to cause the energization of said device, a second switch operated by said device when energized for reversing the direction of current flow over said circuit to operate said signal control relay on the opening of the manual switch, a s1 al' at the central station for indicating the position of said second switch, and means controlled by the operation of said signal control relay for' actuating said signal.

2. A supervisory and control system, comprising a central station, a remote station, an electromagnetic device at said remote stathe operation of said indicators, a circuit including a keywhich when operated shunts said polarized relay thereby causing an in' creased flow of current in said circuit, a marginal relay in said normally closed circuit at the remote station operated by the increased current to closean energizing circuit for an actuating winding of said device,

and means operated by the energization of said device for actuating a switch for opening said normally closed circuit'and closing said normally open circuit thereby disconnectiiig said polarized relay from said normally closed circuit and connecting said polarized relay into said normally open circuit so that current of ne ative" polarity energizes the windingsof t e polarized relay to cause it to actuate said indicators to show the ppsiton of said device.

In witness whereof, I hereunto subscribe my name this 23rd day of November A. D.,

HENRY L. HOFEMANN. 

